Triphenyl monomers suitable for microstructured optical films
Optical films are described having a polymerized microstructured surface that comprises the reaction product of a polymerizable resin composition comprising at least one polymerizable ethylenically unsaturated triphenyl monomer. Also described are certain triphenyl (meth)acrylate monomers and polymerizable resin compositions.
1. A brightness enhancing optical film comprising a polymerized microstructured surface comprising a linear array of prisms wherein the polymerized microstructured surface comprises the reaction product of a polymerizable resin composition comprising a triphenyl monomer having the general structure
wherein R2 is independently H or a substituent comprising a (meth)acrylate group and at least one R2 is a substituent comprising a (meth)acrylate group;
X is independently aryl or a C 2 to C 12 alkyl group; and
p is 0 to 5.
2. The brightness enhancing optical film of claim 1 wherein the polymerizable resin composition comprises less than 1 wt-% total of chlorine or bromine.
3. The brightness enhancing optical film of claim 1 wherein the polymerizable resin is free of inorganic nanoparticles.
4. The brightness enhancing optical film of claim 1 wherein the polymerizable resin comprises at least 10 wt-% of surface modified inorganic nanoparticles.
5. The brightness enhancing optical film according to claim 1 wherein the brightness enhancing optical film has a single sheet gain of at least 1.59.
6. The brightness enhancing optical film of claim 1 wherein R2 is independently a (meth)acrylate substituent selected from
wherein Q is O or S;
L is a C 2 to C 6 alkylene group optionally substituted with a one or more hydroxyl groups;
n ranges from 0 to 10; and
R1 is H or CH 3 .
7. The brightness enhancing optical film of claim 1 wherein the triphenyl monomer is a triacrylate (meth)acrylate monomer having a refractive index of at least 1.50.
8. The brightness enhancing optical film of claim 1 wherein the triphenyl monomer has a refractive index of at least 1.55.
9. The brightness enhancing optical film of claim 1 wherein the triphenyl monomer has a refractive index of at least 1.60.
10. The brightness enhancing optical film according to claim 1 wherein the triphenyl monomer is a liquid at ambient temperature.
11. The brightness enhancing optical film of claim 1 wherein p is 0.
12. The brightness enhancing optical film of claim 6 wherein Q is 0.
13. The brightness enhancing optical film of claim 1 wherein the triphenyl monomer is a mono(meth)acrylate monomer.
14. The brightness enhancing optical film according to claim 1 wherein the polymerizable resin composition comprises
up to 50 wt-% of one or more triphenyl (meth)acrylate monomers; and
25 wt-% to 75 wt-% of one or more multi(meth)acrylate monomers or oligomers having at least two polymerizable (meth)acrylate groups.
15. The brightness enhancing optical film of claim 4 wherein the inorganic nanoparticles have a refractive index of at least 1.68.
16. The brightness enhancing optical film of claim 4 wherein the inorganic nanoparticles comprise zirconia.
17. The brightness enhancing optical film of claim 12 wherein L is C 2 to C 3 and n is 1.
18. The brightness enhancing optical film of claim 13 wherein the triphenyl monomer has the structure
19. The brightness enhancing optical film of claim 14 wherein the multi(meth)acrylate monomer comprises one or more bisphenol A (meth)acrylates, aromatic epoxy (meth)acrylates, and mixtures thereof.